Security fence with secured bolts

ABSTRACT

A fence pale P for a security fence comprises at least one hole  3  to receive a fastener  4  having a head  9  and a shank  8,  with the shank  8  extending through the hole  3  and the underside of the head  9  being in contact with the surface  1  of the pale P, wherein integral shoulder means  20  are located adjacent the or each hole  3,  said shoulder means  20  being shaped to deny access to the underside of the head  9  of a so-received fastener  4,  whereby the fastener  4  cannot be prised away from the pale P.

[0001] The invention relates to a fence pale and in particular to one for use as a security fence.

[0002] It is usual to build a fence of spaced, upright posts joined together by usually horizontal members, referred to as rails. Typically the pales and the rails are made of metal and these are joined together by fasteners, either bolts and nuts or rivets, passing through aligned holes.

[0003] A security fence cannot guarantee absolute security from a determined thief. The thief may try to remove the head of the fastener by use of a sharp tool e.g. a chisel, or prise a fastener from the assembly. The thief needs to be able to get the tool behind the fastener head for this purpose.

[0004] Security fences have been proposed which address this issue, for example, those described and claimed in GB 2241721 and GB 2307493. However, each of the prior art fences requires elements additional to the pale, rail and fastener to achieve the desired result.

[0005] A further security fence, comprising posts and mesh sections has been proposed in GB 2250757. This, similarly, relies on the provision of elements additional to the posts, mesh sections and fasteners. It also discloses the use of fasteners with frangible portions to ensure the heads thereof cannot be attacked.

[0006] It is an object of this invention to provide a solution to this problem, in which a security fence requires a minimum of components, thereby increasing the ease of assembly and reducing the capital cost of manufacture and assembly.

[0007] According to a first aspect of the invention there is provided a security fence comprising two posts, pales and at least one rail, wherein the pales are generally vertical and secured by fastener means to a generally horizontal rail, wherein the pales having at least one hole to receive a fastener having a head and a shank, the shank extending through the hole, the underside of the head being in contact with the surface of the pale, shoulder means being located adjacent the or each hole, the shoulder means being shaped to deny access to the underside of the head of the fastener received in the hole, whereby the fastener cannot be prised away from the pale.

[0008] According to a second aspect of the invention, there is provided a fence pale for a security fence, the pale having at least one hole to receive a fastener having a head and a shank, with the shank extending through the hole and the underside of the head being in contact with the surface of the pale, integral shoulder means being located adjacent the or each hole, said shoulder means being shaped to deny access to the underside of the head of a so-received fastener, whereby the fastener cannot be prised away from the pale.

[0009] The pale may be a cold-formed metal section, preferably steel, shaped to have a longitudinal web and a longitudinal wing portion extending from each side thereof, the hole and shoulder means being present in and on the web respectively.

[0010] It is a preferred feature of the invention that the shoulder means are integrally formed with the pale.

[0011] Preferably the shoulder means comprises two shoulders on diametrically opposite sides of the or each hole, e.g. above and below the hole when the pale is vertical.

[0012] The wing portions preferably extend out of the plane of the web, such that, in cooperation with the shoulders, they deny access from every direction of the so-received fastener, in use.

[0013] Preferably each shoulder comprises a ramp portion rooted remote from the or each hole and inclined upwardly theretowards and terminating in a face portion inclined downwardly towards the or each hole.

[0014] In a further aspect of the invention, there is provided a method of forming a pale comprising cold-rolling steel to form an elongate member having integral shoulder means and forming a hole in the member, the hole being located such that said shoulder means are adjacent thereto.

[0015] A third aspect of the invention provides a method of forming a pale comprising forming a hole in an elongate steel member and cold-rolling that member to form a pale having integral shoulder means adjacent the hole.

[0016] In order that the invention may be well understood it will now be described by way of example with reference to the accompanying diagrammatic drawings, in which:

[0017]FIG. 1 is a plan view of part of the length of a pale;

[0018]FIG. 2 is a section taken on lines II-II on FIG. 1;

[0019]FIG. 3 is a section taken on lines III-III of FIG. 1;

[0020]FIG. 4 is a partial sectional view of an assembly showing a chisel attack on a prior art pale; and

[0021]FIG. 5 is a partial sectional view of an assembly showing a chisel attack on a pale according to the invention.

[0022] The pale P comprises a length of metal section, e.g. steel, cold rolled to have a major web 1 and two side wings 2, the wings 2 extending out of the plane defined by the major web 1. Spaced-apart holes 3 (only one shown) are present in the major web 1 to receive fasteners 4 (FIG. 5) by which a rail 5 is joined to a pale P. The holes 3 may be formed before or after cold rolling. The fasteners 4 are passed through the holes 3 in the pale P and an aperture 6 in the rail 5. Each fastener 4 has a nut or collar 10 to secure the assembly and hold the components P, 5 together.

[0023] According to the invention, shoulders 20 are present on the web 1 on diametrically opposite sides of the hole 3. Each shoulder 20 is generally wedge shaped, as seen in plan, having a wider curved wall 21 near the hole 3. The wall 21 rises relatively steeply from the web 1 and then descends in a ramp portion 22 to merge with the web remote from the hole 3.

[0024] The curved shape of the hole-facing wall 21 allows that wall 21 to at least partially encompass the perimeter of a head 9 of a fastener 4.

[0025] As shown in the top half of FIG. 4, where no shoulder 20 is present, a chisel C can be put behind the head 9 of the fastener 4 to remove the head 9 from the fastener 4 or, alternatively, force the fastener 4 from its' collar 10 and so destroy the assembly.

[0026] In contrast, and as shown in FIG. 5, the shoulders 20 prevent such an attack in a pale P of the invention. The side wings 2 act in concert with the shoulders 20 to ensure that there is no point from which a chisel C may be forced under the head 9 of the fastener 4.

[0027] The invention is not limited to the embodiment shown. More than two shoulders may be present; they need not be of the shape shown. The pale need not be vertical. 

1. A security fence comprising two posts, pales and at least one rail, wherein the pales are generally vertical and secured by fastener means to a generally horizontal rail, wherein the pales have at least one hole to receive a fastener having a head and a shank, the shank extending through the hole, the underside of the head being in contact with the surface of the pale, shoulder means being located adjacent the or each hole, the shoulder means being shaped to deny access to the underside of the head of a fastener received in the hole, whereby the fastener cannot be prised away from the pale.
 2. A fence according to claim 1, wherein each pale comprises a cold-formed metal section having a longitudinal web and a longitudinal side wing extending from each side thereof, the hole and shoulder means being present in and on the web respectively.
 3. A fence according to claim 1, wherein the shoulder means comprises two shoulders on diametrically opposite sides of the or each hole.
 4. A fence according to any of claim 2, wherein the side wings extend out of the plane of the web, such that, in co-operation with the shoulder means, they deny access from every direction of the fastener received in the hole.
 5. A fence according to claim 1, wherein each shoulder comprises a ramp portion rooted remote from the or each hole and inclined upwardly theretowards and terminating in a face portion inclined downwardly towards the or each hole.
 6. A security fence pale, the pale having at least one hole to receive a fastener having a head and a shank, with the shank extending through the hole and the underside of the head being in contact with the surface of the pale, shoulder means being located adjacent the or each hole, the shoulder means being shaped to deny access to the underside of the head of a so-received fastener, whereby the fastener cannot be prised away from the pale.
 7. A pale according to claim 6, comprising a cold-formed metal section having a longitudinal web and a longitudinal side wing extending from each side thereof, the hole and shoulder means being present in and on the web respectively.
 8. A pale according to claim 6, wherein the shoulder means comprises two shoulders on diametrically opposite sides of the or each hole.
 9. A pale according to claim 6, wherein the side wings extend out of the plane of the web, such that, in co-operation with said shoulder means, they deny access from every direction of the so-received fastener, in use.
 10. A pale according to claim 6, wherein each shoulder comprises a ramp portion rooted remote from the or each hole and inclined upwardly theretowards and terminating in a face portion inclined downwardly towards the or each hole.
 11. A method of forming a pale according to claim 6, the method comprising cold-rolling steel sheet to form an elongate member having integral shoulder means and then forming a hole in the member, the hole being located such that said shoulder means are adjacent thereto. 